jakematic

Yep, sounds exactly like mine

LOL sorry I didn't mean to direct that at you, but intead the comments on the linked site.

It bugs me when I hear that from a 2nd, 3rd, 4th etc owner who paid WAY less than the first one
Can be a real eye roller over in D3 for sure.
Folks with freshly purchased/leased vehicles have more leeway to bitch about price/quality in my book; but then we just go back to Audi and do that usually.

Will be most interested to hear what you find out on the hum issue.
I've always assumed it was my horrible Goodyear tires, but there aren't a lot of choices to move to.
On the other hand I'll be in a 2015 soon enough and have a different set of things to ponder...

Keep us posted on your findings !

needles

Wow... I am crossing my fingers I never hear that.

jakematic

You'll know if you do - the second you hit the 'right' kind of road, and the second you leave it.

I have the Goodyear Assymetrics, and didn't move to the Conti's thinking there wouldn't be any difference because they both have giant grooves in the treads.
Also didn't feel the need to spend $8k to replace brands new wheels and tires to downsize to a 19"

Several knowledgeable friends who are serious track racers feel it's the tires.
A good friend who is a manager at Goodyear looked at mine after I mentioned it to him and said Goodyear doesn't make that style in other sizes anymore, calling it the 'non-improved' version.

I'm not sure either way.

autiant

I had this noice with Goodyear and changed my tyres to Continental but still I can hear it. Continental is a little bit more silent but not as silent than I wanted...

needles

Oh, I've heard this in the A8 and my Infinitis on roads that are being resurfaced and are "grooved" parallel to the direction of the interstate. There's no way around this sort of sound because the channels are so deep.

But on regular pavement? I'd never accept a car that made that noise on normal highways/streets.

jakematic

Exactly what I figured reading the Tire Rack reviews.


Me either, mine does it on grooved roads only - almost silent the rest of the time.
The first time you roll onto that type of road you think 'HOLY ___ what's wrong?'

I must say I was spoiled by my 19" Conti DW tires on the D3.
They were ultra quiet and performed like a rat on velcro.

ffejrey

Lucky you!! I wrote this earlier but to repeat, repeat - I read and was told by the dealership the 2015 (in addition to everything else...) has "mass dampeners" added to the struts, additonal sound deadening material and noise cancellation technology.

Also to repeat, when my car was at the dealership they took the 19's off their 2015 A8 NWB loaner and put them on my car. I asked them then if I could take the loaner for a day with my wheels and tires on it... They did which was again super cool all things considered (well besides them incorrectly blaming tires) Guess what!! There were only a couple of instances I heard the noise begin and stopped almost immediately after. Those dampeners are doing their work... This redesign to me is however a clear sign of two things

1. Vibration/Harmonics are being transferred... Otherwise the dampener would have no effect on tire noise. The dampener can only affect what is 'after' its placement within the strut...

2. Audi felt the suspension of 2011-2014 D4's needed improvement...

ffejrey

I have a friend who races BMW's and owns San Diego BMW, Mercedes, Audi, VW and European Car Repair Midnight Oil Motorsports |... They also thought it was "tire noise" initially but unfortunately there is more complexity to it... My theory is that the vibration and sound produced by the tire is being harshly translated to the strut and somewhere something is acting like a tuning fork. If it was the nature of 20" wheels then why does the Tesla with 21's, the BMW 740/50 with 20's, and even a Ford Flex with stock 255/40/20's makes no noise on the same freeway surfaces... These are other cars I have driven and been in...

To debate the tire theory -

1. The noise is clearly only occurring in the front of the vehicle. I sat in the back of my car, drove through problem areas, and stuck my ear to the rear tire well as much as possible (Heck I'll get in the trunk at this point!). Only when my head cleared the rear seats and I poked my head into the front of the car did the sound increase dramatically. Changing tires front to back have no effect where the sound occurs - it's always in the front of car.

2. Tire harmonics are generated and perpetuated by a number of factors... a lot I do not know or understand. What I do know is that:

A. the rubber compound of the outer tire affects grip, friction and resulting road noise.

B. The inner tire construction and the sidewall firmness create more harsh conditions for harmonics and sounds to occur (summer tires are much stronger internally than touring), like a drum skin.

C. The volume of the tire can act as a "Drum-like" instrument.

D. The tread pattern and air movement through the treads can also create harmonics, and noises.

Now... Consider that I changed my tire manufacturer and therefore tread pattern, I changed from a summer tire to a a/s so sidewall firmness has decreased, I changed the sidewall height from 4.1 to 4.3 inches, and I changed to a 275/40/20 tire from 265 and therefore changed the airspace within the tire.

With all that done, and again only from the front of the vehicle, the same frequency sounds are being produced. A bigger drum would make a lower frequency, and a different tread pattern generates different sounds and harmonics inherently...

Also what I feel is an extremely important observations is when this vibration is present and I go over a bump there is a hollow donking noise (which I believe may be similar/same to others "whoop" phenomenon) in place of the . flat "clunk clunk clunk" noise that we all experience when lane changing with markers. I believe this is what will happen to other cars the more mileage and bad roads they are driven on... but I hope not. It sounds like most cities do not have as much grooved freeways and other poor road surfaces such a mine.

Finally as mentioned in the car and driver article there is a big performance drop from 20's to 19's:

"The P Zeros did at least enable amazing performance figures of *0.90 g on the skidpad and 152 feet braking from 70 mph, both of which improved slightly in our final test. Noise reduction comes with a penalty: A test of a 2013 A8L on all-season tires yielded 0.85 g in cornering  grip and a 172-foot stop from 70 mph."

2012 Audi A8L 4.2 FSI Quattro Long-Term Test Wrap-Up ? Review ? Car and Driver

So... for Audi to tell us to spend money and downside tires to make the car quieter also changes the characteristics of the car dramatically and why many of us purchased such a dynamic vehicle...

ffejrey

I am very curious that you say your infinitis as well. When I drive other cars over the same road surfaces I hear plenty of flat tire noise but not the harmonics and the decibel level we hear inside the vehicle. Again I have driven in multiple cars with 20" and beyond wheels with even smaller side wall height.

Of course every car will make loud noises when you hit rumble strips on the edge of certain freeways and other "poor" road surfaces... My A8L sings to me for more than 50% of my commute from San Diego to Los Angeles. In LA it's a nightmare... My BMW 740 and Subaru STI never made any sounds even remotely similar (and still do not in fact!)

ffejrey

Are the noises you hear before and after changing tires the same frequency?